No. You have to assume worst case if you are serious.
More people together of like mind will help, but injuries and death will reduce numbers. Neighborhood watches now can help to train you guys to work together. Learn to use radios to communicate. Analyze strong and weak points of the neighborhood. Have fallback plans in case people in bad areas need to get to anothers’ house. Generally don’t leave the strongest place.
If you’re not going to have a plan to leave, you have to plan for the extreme. It’s all you are going to have. ANd you will need a few others to help you because on-two people will not last against an armed group very long.
The idea you are talking about is going to work well for rural people who know each other and will by then be living in fortified homes and have already had relatives and others get there with goods and weapons and will be a little force of their own. Not nearly as well in the cities or suburbs. It’s more of an urban warfare issue. Too many ways to get to you in the city or suburbs. Not much distance and time before an attack.
Well......you are right of course. But to give up so much now to prepare for such an extreme (I don't at all mean impossible) future will require some more thought. This bad thing can happen in a lot of differnt ways, and a lot of other, unrelated bad things can, and do, happen.
If you’re not going to have a plan to leave,
__________
That plan we do have and it’s complete.